It is known to provide food products such as yogurt in plastic containers having sealed foil covers. However, the price of plastic used to manufacture such containers is closely tied to the price of oil which, for a number of years has seen a steady upward trend. It is therefore desirable to use paper containers provided they can meet the requirements associated with the packaging of food products. A problem with the use of paper is the attachment of a heat sealable foil cover to the container. That process requires a flat annular rim around the top of the container capable of sustaining a wide range of pressures and temperatures during the filling process of the food product. Paper alone does not provide this.